Currently, EMG (electromyographic) systems used in gait analysis laboratories are bulky, heavy, and cumbersome (especially for small children). Electronic components are constantly being miniaturized, yet EMG manufacturers have not yet been innovative enough to utilize current technology to improve their systems. Ramsey Electronics is a leader in the field of miniaturized wireless technology. The purpose of this investigation is to develop a miniaturized EMG system, in conjunction with Ramsey Electronics, which will answer the need for improved EMG signal collection. We will use proven techniques and devices to form an innovative system for EMG data collection. The pilot study used a transmitter the size of a postage stamp located on the surface electrode. We propose to develop a miniaturized EMG system by implementing the following Specific Aims: Specific Aim 1: Develop and test a single channel EMG miniaturized telemetry system. Task 1: Develop and test a single channel EMG miniaturized telemetry system. A miniature transmitter and receiver from Ramsey Electronics will form the nucleus of this unit. Task 2: Test the single channel EMG unit. These tests will include bench tests with known signals, human testing, and simultaneous data collection and comparison with existing commercial EMG equipment. Specific Aim 2: Integrate and test B EMG units into a miniaturized telemetry system. Task 1: Integrate 8 EMG units into a miniaturized telemetry system. The frequency separation necessary to permit the operation of multiple units will be determined. Task 2: Test the 8 EMG channels. The performance of the 8 channel unit will be systematically evaluated using tests similar to those described in Aim 1. PROPOSED COMMERCIAL APPLICATION: A miniaturized wireless EMG device will be a valuable alternative to existing commercial EMG equipment. The small size and low weight will benefit disabled children whose balance is already precarious; this will aid gait labs by increasing the reliability of data collected from smaller patients. The lack of encumbering wires will be useful to ergodynamics labs and sports medicine labs. Extremely small wireless data transmitters will benefit other areas in rehabilitation, stroke and spinal cord patients, physical therapy, and biofeedback when the idea of data transmission direct from the sensor is more accepted. Ultimately, stress labs and Cardiology step-down units will benefit from miniaturization of their existing telemetry units.